The present invention relates to a poppet valve, more particularly, a poppet valve used in a dispensing valve assembly.
In an injection-molded dispensing valve assembly, a poppet valve having a supporting member is generally disposed in a fluid passageway extending through the dispensing valve assembly. The fluid passageway in the dispensing valve assembly is opened or closed by relatively reciprocating the poppet valve. The poppet valve usually displaces o-rings or other types of integral sealing members in its reciprocating movement thus establishing a seal between the poppet valve and the sealing members. Long term displacement of the sealing members may cause permanent deformation of the seal. Therefore, it is desirable to minimize the stresses placed on the sealing members.
The o-rings or sealing members are easily worn out or permanently deformed by a support member of the poppet valve because the supporting member has sharp corners. When the o-ring or sealing member slides over the supporting member, the deformation is caused. Thus, it is desirable to minimize the incidence of sharp corners on a molded poppet. Sharp corners result from the molding of the supporting member when two molding pieces abut one another to form a closed cavity into which a plastic resin is injected. The degree to which the sharp corner is present is the result of how closely the molding pieces fit together.
Researches and experiments, which are disclosed in xe2x80x9cPARKER O-RING HANDBOOKxe2x80x9d pp A4-6, discloses that the sealing element, such as o-ring, should never be forced over sharp corners, threads, keyways, slots, splines, ports or other sharp edges. Failure analysis, which are disclosed in xe2x80x9cPARKER O-RING HANDBOOKxe2x80x9d pp A9-4, proves that the damage to an o-ring during installation can occur when:
1) there are sharp corners on mating metal components such as the o-ring gland or threads over which the o-ring must pass during assembly;
2) there is insufficient lead-in chamfer; and
3) there are blind grooves in multi-port valves; etc.
As shown in FIG. 4A, there is a conventional poppet supporting member 200 molded by two molding pieces 206,208. It is impractical to eliminate the sharp corners 202,204 on the poppet supporting member 200, and it is impractical to mold a radiused edge in an area where the molding pieces 206,208 come together and where a tool parting line is present. Thus, when the poppet supporting member 200 is reciprocated in the dispensing valve assembly, the o-rings or other integral molded sealing members slide over the sharp corners 202,204 as shown in FIGS. 6A and 7A. Thus, the o-rings or other sealing members are very easily worn out or permanently deformed.
In addition, when the sharp coners 84 as shown in FIG. 8A are disposed on the inside wall of a valve assembly, the o-rings or other types of sealing members, which slidably come in contact with the sharp comers 84, are also easily worn out.
In FIGS. 4B and 4C, an accepted conventional practice is shown, wherein the xe2x80x9cfeather edgexe2x80x9d (212) is added in the parting line area of the inner molding piece 208. It is often difficult and costly to produce the molding tool piece with the xe2x80x9cfeather edgexe2x80x9d (212) initially, and it is prone to considerable wear and even damage in use.
It is accordingly the object of the present invention to provide an improved poppet valve that overcomes the deficiencies of the prior art.
The present invention relates to a supporting member of a poppet valve, more particularly, the supporting member of the poppet valve used in a dispensing valve assembly.
In one embodiment of the present invention, a supporting member of a poppet valve in a dispensing valve assembly includes a main body having at least one longitudinal edge and a flexible flap disposed along the longitudinal edge. The flexible flap may cooperate with a sealing portion of the dispensing valve assembly. The flexible flap may distribute an interference force exerted by the main body on the sealing portion, wherein the sealing portion may not be damaged or deformed.
In one embodiment of the present invention, the supporting member may be disposed within a housing of the dispensing valve assembly.
In another embodiment of the present invention, the resilient flap may be integrally formed on the longitudinal edge of the supporting member.
In another embodiment of the present invention, the resilient flap may be formed of a generally radius shape.
In one embodiment of the present invention, a supporting member of the poppet valve is molded by an inner molding piece, which has a reduced portion, and an outer molding piece. The poppet supporting member thus formed has a resilient flap around the area where the molding pieces interface. The flap is able to deform so as to distribute the interference forces translated to the sealing members or o-rings over a larger area thereby reducing the stress on the seal or o-ring itself. The reduction in stress may prevent permanent deformation or damage to the sealing member or o-ring.
Still in one embodiment, the supporting member of the poppet valve includes a main body that may be a longitudinal beam. The resilient flap is integral to two longitudinal edges oppositely disposed on the longitudinal beam.
In one embodiment, the supporting member of the poppet valve is disposed in a fluid passageway extending through a dispensing valve assembly. The poppet valve is relatively reciprocated inside the dispensing valve assembly to open or close the fluid passageway.
In another embodiment of the present invention, a plurality of o-rings or other types of sealing members are disposed along the fluid passageway of the dispensing valve assembly. The o-rings or sealing members slide over the supporting member of the poppet valve as it is reciprocated. The resilient flap of the supporting member distributes the stress between the supporting member and the o-rings or sealing members so as to prevent permanent deformation on the o-rings or sealing members.
In one embodiment, a molding piece for molding a side port on an inside wall of the dispensing valve assembly has round comers so as to form flaps at the opening of the side port. When the o-ring or sealing member slides over the flaps, the flap is bent so that the o-ring or the sealing member is prevented from being permanently deformed.
In one embodiment of the present invention, a dispensing valve assembly includes a housing defining a longitudinal fluid passageway through the housing, and an insert member having a sealing portion. The insert member may be insertable into the housing, and may define a second fluid passageway in fluid communication with the fluid passageway of the housing. A poppet valve may be disposed along the first fluid passageway and in fluid communication with the first and second fluid passageways. The poppet valve may include a supporting member having a main body including at least one longitudinal edge. A flexible flap may be disposed along the longitudinal edge, and may cooperate with the sealing portion of the insert member. The flexible flap may distribute an interference force exerted by the main body upon the sealing portion, wherein the sealing portion is not damaged or deformed.
These and various other advantages and features of novelty which characterize the invention are pointed out with particularity in the claims annexed hereto and forming a part hereof. However, for a better understanding of the invention, its advantages and objects obtained by its use, reference should be had to the drawings which form a further part hereof, and to the accompanying descriptive matter, in which there is illustrated and described a preferred embodiment of the invention.